The field of this invention is buoys and the like.
In offshore drilling and production operations it is often desirable to transport equipment to an offshore location without actually loading the equipment on board a ship or other vessel. This is particularly true where flowlines are to be transported to an offshore well.
However, problems were encountered when the transported equipment was merely floated at or near the ocean surface using conventional buoys or the like. Often rough seas were encountered during the transportation of the equipment, and the wave action created forces which damaged or destroyed the transported equipment. Even where the equipment was suspended slightly below the ocean surface and supported by buoys which floated at the surface, the forces of the wave action on these surface buoys were transmitted to the transported equipment unless special assemblies were employed to absorb such wave action forces.
When the transported equipment had to be lowered to the ocean bottom after arriving at the offshore location, additional problems were encountered with the use of conventional surface buoys. Typically, such buoys would only support the transported equipment at or near the ocean surface. If the transported equipment was disengaged from the buoys, it simply fell to the ocean floor. Where the transported equipment was a flowline, this method of lowering the flowlines to the ocean bottom often resulted in kinking the flowlines and otherwise damaging them. Similarly, other equipment was often damaged if it was merely allowed to fall to the ocean bottom. While one tool was developed for use in conjunction with surface buoys so that the equipment being lowered would fall slowly through the water, a great deal of care had to be exercised in utilizing this tool.